docstr: Returns a list of the variables that are trainable.
  
  Returns:
      trainable_variables: a tuple of `tf.Variable`.
docstr_tok: ["Returns","a","list","of","the","variables","that","are","trainable",".","Returns",":","trainable_variables",":","a","tuple","of","`","tf.Variable","`","."]
code: def get_trainable_vars(self):
      """
      Returns a list of the variables that are trainable.
  
      Returns:
          trainable_variables: a tuple of `tf.Variable`.
      """
      return snt.get_variables_in_module(self)
  
file_path: luminoth/luminoth/models/ssd/feature_extractor.py
imports: import sonnet
  import tensorflow
  from sonnet.python.modules.conv import Conv2D
  from tensorflow.contrib.layers.python.layers import utils
  from luminoth.models.base import BaseNetwork
label_desc: Use image node_id 4 for calling the SSDFeatureExtractor obj's underlying member method code with example usage: obj.get_trainable_vars() and returns: snt